<!doctype html>
<html>
<head>
  <title>Graph 3D camera position</title>

  <style>
    body {font: 10pt arial;}
    td {font: 10pt arial}
  </style>

  <script type="text/javascript" src="../../dist/vis.js"></script>

  <script type="text/javascript">
    var data = null;
    var graph = null;

    function custom(x, y) {
      return (Math.sin(x/50) * Math.cos(y/50) * 50 + 50);
    }

    // callback function, called when the camera position has changed
    function onCameraPositionChange() {
      // adjust the values of startDate and endDate
      var pos = graph.getCameraPosition();
      document.getElementById('horizontal').value = parseFloat(pos.horizontal.toFixed(3));
      document.getElementById('vertical').value   = parseFloat(pos.vertical.toFixed(3));
      document.getElementById('distance').value   = parseFloat(pos.distance.toFixed(3));
    }

    // set the camera position
    function setCameraPosition() {
      var horizontal = parseFloat(document.getElementById('horizontal').value);
      var vertical = parseFloat(document.getElementById('vertical').value);
      var distance = parseFloat(document.getElementById('distance').value);
      var pos = {
        horizontal: horizontal,
        vertical: vertical,
        distance: distance
      };
      graph.setCameraPosition(pos);

      // retrieve the camera position again, to get the applied values
      onCameraPositionChange();
    }

    // Called when the Visualization API is loaded.
    function drawVisualization() {
      // Create and populate a data table.
      data = new vis.DataSet();
      // create some nice looking data with sin/cos
      var steps = 50;  // number of datapoints will be steps*steps
      var axisMax = 314;
      var axisStep = axisMax / steps;
      for (var x = 0; x < axisMax; x+=axisStep) {
        for (var y = 0; y < axisMax; y+=axisStep) {
          var value = custom(x,y);
          data.add([
            {x:x,y:y,z:value,t:0,style:value}
          ]);
        }
      }

      // specify options
      var options = {
        width:  '600px',
        height: '600px',
        style: 'surface',
        showPerspective: true,
        showGrid: true,
        showShadow: false,
        keepAspectRatio: true,
        verticalRatio: 0.5
      };

      // create our graph
      var container = document.getElementById('mygraph');
      graph = new vis.Graph3d(container, data, options);

      graph.on('cameraPositionChange', onCameraPositionChange);
    }
  </script>
  
</head>

<body onload="drawVisualization()">
<h1>Graph 3d camera position</h1>
<table>
  <tr>
    <td>Horizontal angle (0 to 2*pi)</td>
    <td><input type="text" id="horizontal" value="1.0"></td>
  </tr>
  <tr>
    <td>Vertical angle (0 to 0.5*pi)</td>
    <td><input type="text" id="vertical" value="0.5"></td>
  </tr>
  <tr>
    <td>Distance (0.71 to 5.0)</td>
    <td><input type="text" id="distance" value="1.7"></td>
  </tr>
  <tr>
    <td></td>
    <td><input type="button" value="Set" onclick="setCameraPosition();"></td>
  </tr>
</table>

<div id="mygraph"></div>

<div id="info"></div>
</body>
</html>
